Tardigrades Produce Glass Shields to Survive Extreme Conditions

Nothing the tardigrade does could really surprise us at this point. Scientists now say the microscopic critters produce “glass shields” inside their cells to protect vital chemicals from drying out. They published their report on the tardigrades’ latest bizarre talent in the journalMolecular Cell.

Tardigrades, also known adorably as water bears or moss piglets, may be the most extreme organisms on or off this planet. When the going gets tough—whether that’s high heat, freezing cold, extreme dryness, or the vacuum of space—tardigrades dry up and shut down, going into a near-death state called cryptobiosis. Later, when the environment is livable again, they spring back to life like tiny, many-legged Snow Whites. Exactly how they pull this off has remained something of a mystery.

There are other organisms that can survive drying up and rehydrating. Many of them do so by producing a sugar called trehalose, which vitrifies, or turns into glass, inside their cells, creating a protective coating around life-sustaining proteins and other molecules.

But not all tardigrade species can make trehalose—which suggested to scientists that the water bears might produce their own proprietary material to keep their molecules safe.

Researchers pored over the genomes of the commonly studied tardigrade species Hypsibius dujardini and Paramacrobiotus richtersi looking for genes that might let the critters pump out some form of protective gear.

They found a few. Drying out the tardigrades prompted both species to switch on genes associated with weird chemicals called intrinsically disordered proteins (IDPs). The specific IDPs were, unsurprisingly, unique to tardigrades and haven’t been seen in any other organisms.

If we can figure out how to harness these genes, the authors say, we could solve big problems in keeping both crops and biomedical samples safe in extreme conditions.